<template>
    <div class="cmt-container">
        <h3>评论区</h3>
        <hr>
        <textarea placeholder="请输入要评论的内容（最多120字）" maxlength=120 v-model="msg"></textarea>
        <mt-button type="primary" size="large" @click="postComment">发表评论</mt-button>

        <div class="cmt-list">
            <div class="cmt-item" v-for="(item, index) in comments" :key="index">
                <div class="cmt-title">
                    第{{ index + 1 }}楼&nbsp;&nbsp;用户：{{ item.user_name }}&nbsp;&nbsp;发表时间：{{ item.add_time | dateFormat }}
                </div>
                <div class="cmt-body">
                    {{ item.content === 'undefined' ? '什么也没留下' : item.content }}
                </div>
            </div>
        </div>

        <mt-button type="danger" size="large" plain @click="getMore">加载更多</mt-button>
    </div>
</template>

<script>
import { Toast } from 'mint-ui' 

export default {
    data() {
        return {
            pageIndex: 1,
            comments: [],
            msg: ''
        }
    },
    created() {
        this.getComments()
    },
    methods: {
        getComments() {
            this.$http.get('api/getcomments/' + this.id + '?pageindex=' + this.pageIndex)
            .then(result => {
                if (result.body.status === 0) {
                    // 旧数据拼接新数据，而不是直接覆盖
                    // this.comments = result.body.message
                    this.comments = this.comments.concat( result.body.message )
                } else {
                    Toast('加载评论信息失败！')
                }
            })
        },
        getMore() {
            this.pageIndex++
            this.getComments()
        },
        postComment() {
            if (this.msg.trim().length === 0) {
                return Toast('评论内容不能为空！')
            }

            // params 1: 请求的 URL 地址
            // params 2: 提交给服务器的数据对象
            // params 3: 定义提交表单时表单的数据格式 { emulateJSON: true }
            // this.$route.params.XX 从 URL 地址中获取指定数据
            this.$http.post('api/postcomment/' + this.$route.params.id, {content: this.msg.trim()})
            .then(function (result) {
                if (result.body.status === 0) {
                    var cmt = {
                        user_name: '匿名用户',
                        add_time: Date.now(),
                        content: this.msg.trim()
                    }

                    this.comments.unshift(cmt)

                    this.msg = ''
                } else {
                    Toast('发表评论失败！')
                }
            })
        }
    },
    props: ["id"]
}
</script>

<style lang="scss" scoped>
    .cmt-container {

        h3 {
            font-size: 20px;
        }

        textarea {
            font-size: 14px;
            margin: 0;
        }

        .cmt-list {

            .cmt-item {
                font-size: 13px;
                margin: 5px 0;

                .cmt-title {
                    line-height: 30px;
                    background-color: #ccc;
                }

                .cmt-body {
                    line-height: 30px;
                    text-indent: 2em;
                }
            }
        }
    }
</style>